Smoking and Obesity Together Accelerate Multiple Sclerosis Progression

Smoking and obesity are each linked to worse MS outcomes, but their combined impact is unclear. Researchers from the Karolinska Institute analyzed records from 3,300+ people with MS in the Swedish MS Registry. Disability (Expanded Disability Status Scale (EDSS)), physical changes (MS Impact Scale), and cognition (Symbol Digit Modalities Test) were measured.

Smoking and obesity each increased disability progression; smoking also increased risk of cognitive impairment. Their combined effect was much stronger:

• The risk of reaching EDSS 4 (noticable disability but able to walk without an aid) was 21% higher in smokers, 33% higher in those with obesity, and 86% higher in people who were both smokers and obese.

• Both smoking and obesity are modifiable risk factors. Addressing these risk factors—through quitting smoking, improving diet, or increasing physical activity—could slow progression and improve outcomes in MS.

The Expanded Disability Status Scale (EDSS) is the most widely used tool for measuring disability progression in people with multiple sclerosis (MS).

Reference:  Eva, J., Olsson, T., Alfredsson, L., & Hedström, A. K. (2025). Smoking and Obesity Interact to Adversely Affect Disease Progression and Cognitive Performance in Multiple Sclerosis. European Journal of Neurology, 32(2), e70058.

Image Reference: HSCT Hospital India

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